Jet-propelled aircraft with boundary layer control



Sept. 25, 1951 B0 KLAS OSKAR LUNDBERG 2,568,813

JET PROPELLED AIRCRAFT WITH BOUNDARY LAYER CONTROL 6 Sheets-Sheet 1 Filed Nov. 29, 1945 Sept. 25, 195 B0 KLAS OSKAR LUNDBERG 3 JET-PROPELLED AIRCRAFT WITH*BOUNDARY LAYER CONTROL Filed Nov. 29, 1945 a Sheets-Sheet 2 6 Sheets-Sheet 5 Sept-25, 1951 B0 KLAS OSKAR LUNDBERG JET-PROPELLED AIRCRAFT WITH BOUNDARY LAYER CONTROL Filed Nov. 29, 1945 P 1951 B0 KLAS OSKAR LUNDBERG 2,568,813

JET-PROPELLED AIRCRAFT WITH BOUNDARY LAYER CONTROL 6 Sheets-Sheet 4 Filed Nqv. 29, 1945 P 1951 B0 KLAS OSKAR LUNDBERG 2,568,813

JET-PROPELLED AIRCRAFT WITH BOUNDARY LAYER CONTROL Filed Nov. 29, 1945 6 Sheets-Sheet 5 Sept. 25, 1951 B0 KLAS OSKAR LUNDBERG 2,568,813

JET-PROPELLED AIRCRAFT WITH BOUNDARY LAYER CONTROL.

Filed Nov. 29, 1945 a Sheets-Sheet 6 I l' i '7' h I10 Patented Sept. 25, 1951 JET-PROPELLED AIRCRAFT WITH BOUNDARY man a CONTROL -Bo- Klas-skar Lundberg, Appelviken, Sweden, assignor toSv-enska Turbinfabriks Aktiebolaget Liun tmm, E spo we aco pp t tiqn.

of Sweden Application November 29, 1945,-S erial No. 631,642 In Sweden September. 28, 1945 21 Claims. 01.244

In-reactive operation'ofaircraft, the facilities dorimproving thepropertiesof the. aircraft by boundary layer controllare far greater per se than in air screw propulsion. In the.practical application, certain difficulties. are met with, :however, particularly. in regard to .such suckingoif oftheboundary layer. that has. for its .object tosincr-ease the buoyancy. of the wing at a low speed or to increase the .maximum coefficient of buoyancy .thereof.-:for..the' purpose of reducing 'the'speedin landing-and thus the landing run required. In. the :sucking .of .air from the boundar-ylayer with the .aidlof .thesource of power of the jet propulsion .unit a propelling reaction force manifests itself atLthe sametime, whichis thee-force generated. bythereaction gases ejected rearward from .the-.unit,. andlthis force should of course be reduced in-.=flying.- for. landing as well asiduring the actual touch-down manoeuvre, in order-to reducethespeedas far: aspossible. contradistinction 130: this, theaunit should. developa largeamountof energy...to.suck away the =boundaryilayerson. the same occasion. It is desirable, furthermore, that .in flying for landing the gliding angle. be comparatively steep, .a propelling.- force being then. also detrimental, inasmuch as it -makes;the..gliding angle flatter.

The present invention has for its object to solve the problem of regulating the. boundary :layerby means of .a jet propulsion unit or exhaust-gas-propelledcompressor plant at an aircraft at simultaneous reduction of the propelling reactive force to an arbitrary desired value, which may alsobe. naught or negative, that is to say a value. atthe production of a. rearward directed reaction force. The. invention may be applied toyaircraft having a jet propulsion unit with a-turbine-driven compressor for the com- :hustion air or with simple reaction tubes without anymovable parts or with means comparable therewith. The substantially distinguishing feature. of the invention is, above all, that the re- .eption unit or the like is arranged to control .(accelerate, suck and/or blow off) the boundary layer of the aircraftpreferably that of the :wings-and that the compressor or the like'is adapted-to be utilized for simultaneous reduc- 2 laterallydirected subordinate outlets. The latter means may consist of deflecting members adapted to deflect the gases from the jet propulsion unit in directions. other than the nor malone, for instance laterally or forwardlydn thejvertica ;v direction or, obliquely forward, and this-deflectin member .may be adjustable in suchmanner that the substantially rearwarddirected reaction force produced by the deflection maybe varied fromnaughtto a maximum value. It will be possible herebyto increase thflbllQY- an'cy of the aircraft, while the propelling reaction force is reduced at the sametime, or, the braking'effect is at thesame time exerted by the rearward directed reaction force. The effect of such reactive braking, which is desirable, above all, in connection with landing, butmayrbe of importance also, for, example for the reduction of the speed during ordinary flight, wilLqbe appreciably augmented by a simultaneous control of 'the boundary layenpartly because of the fact that the latter involves a lower stall limit, so that the reactive braking may beapplied more powerfully and during a longer period, before any risk "is incurred of the stalling of the aircraft, andpartly for the reason that the'wings entail a greater air resistance at said coefficient of buoyancy involved bytheboundary layer control than without any boundary layer control.

Further features of; the invention and advantages inherent therein will appear from the following description of forms of embodiment illustrated diagrammaticallydn the accompanying drawings. Fig. 1-shows the fuselage and one wing o f-an airplanewith an arrangement according to a first embodiment of the invention inplan view and partlyin section. Fig. 2'shows a cross section on line IIII in Fig. 1. Fig. 3 shows an airplane in thesame manner as Fig. 1 but with an arrangement according toasecond embodiment of the invention. 'Fig. '4 shows a cross section online IVIV-in Fig. 3 and Fig. 5'

a corresponding cross section according :to a modified embodiment. 6 shows a wing in section at'right angles: to theplane of the'wing, and- Fig. 7' shows the -:wing;in horizontal projection and'partly in longitudinal section, saidwing having a jet propulsion unit.with an arrangement accordingstorthein'vention built into the-same. FignB is a perspective view of the-controlling means for the, reactivebraking and theboundary layer control with operatingmembersfor the latter, and Fig. 9 likewise is aperspiective view of adetail oithe;arran ementacq d mafia- 18- "Eia: 10 alpartially sectioned perspective view 5.56am p 3 of operating means for a braking and boundary layer control device according to Figs. 6 and 7. Fig. 11 shows a modification of a detail of the arrangement according to Fig. 10. Fig. 12 illustrates a further embodiment in longitudinal sectlon through an airplane.

Fig. 1 shows the invention as applied to an airplane having a jet propulsion unit arranged centrally on the fuselage l of an airplane, the wings of which are designated by 2. The jet propulsion unit is provided with front air-intakes 3, through which the air is supplied to the suction side of a compressor 4, which is driven by means of a turbine 5. Provided between the compressor 4 andthe turbine 5 is a combustion chamber 5, wherein the combustion of fuel introduced into the same is effected by means of the air compressed by the compressor 4. The combustion gases escape rearward through an outlet passage 1 surrounded by the rear portion 8 of the fixed wall of the jet propulsion unit. This wall forms an outlet 9 for the gases.

The airplane is provided with means facilitating the utilization of the compressor for the control of the boundary layer of the wing and for reducing the propulsive reaction force, which is generated by the combustion gases rushing out in a rearward direction or for producing a braking reaction force. Means are provided to reduce the propelling reaction force and to produce the braking reactive effect, said means causing the' gases escaping through the outlet 9 to flow out in other directions than rearward. According to Fig. 1, these means consist of a pair of deflector flaps I0, I I, which are mounted on the stationary wall 8 so as to permit of being swung about a vertical shaft l2. In normal flight, these flaps take the position shown by full lines, but

they may also be extended into any of the positions a and b or other intermediate positions,

whereby the gas stream is deflected sideways, entirely or in part, and obliquely forwards, as indicated by the arrows l3 and I4.

' For the boundary layer control there are provvided conduits l5, IS in the wing, said conduits duits I8, 20 arranged in pairs above each other and opening into slots 2| and 22, respectively, arranged behind one another in the covering of the wing immediately in front of the rear edge 'of the wing. Similar branch conduits 23, 24 extend from the conduit IE to slots 25 and 26, respectively, the latter being preferably arranged approximately in alignment with the slots 2|, 22

but nearer to the fuselage than the latter slots. On the whole, the drawing only illustrates conduits and suction slots in the one wing, but it is obvious that similar means are to be provided in the other wing as well. Valve members or dampers 21 are provided at the mouths l1, [8 on each side of the passage 29 extending from the air-intakes 3, said dampers being adapted to be adjusted by means of any suitable contrivance in such manner as to be caused to open when air is to be sucked through the conduits l5, l6 from the boundary layer of the wingby means of the compressor 4. The passages l5, l6 have their mouths l1, l8 situated immediately adjacent to controlled by means of a common damper. The

latter is provided opposite the mouth H! with a projecting part or valve body 28 which is within the mouth l8 when the damper is closed. When the damper is swung out from the mouths, the

mouth I! is first opened, the valve body 23 keeping the mouth l8 closed initially. Consequently, a separate control is obtained for the conduits l5 and IS, in a manner such that a variation of the boundary layer control is attained longitudinally of the span of the wing, that is to say in such manner that a boundary layer actuation is switched in, commencing at thepoints of the wings, in order to manifest itself only later on at the inner portion of the wing, when the mouth [8 of the passage 16 is uncovered by the valve body 28.

The adjustment of the damper 21 may be effected manually or by means of automatically acting members, the adjustment of which is dependent on the speed of the airplane relatively to the ambient air. In principle, these members may be constructed as speed indicators. In the embodiment according to Fig. 1 an automatically operating device is shown by way of diagrammatic representation. This device consists broadly of a plunger or pressure plate 30, which is movable against the action of a spring 3| in a forwardly open cylinder 32 located in the front edge of the wing. The plunger'is connected by a rod 33 to the one end of a double-armed lever 34 which is pivoted about a fixed shaft 35, and the other end of which is pivotally connected to a lever 36 secured to the damper 21. When the airplane has its normal velocity, the plunger 30 is kept depressed by the air pressureacting upon the same, so that=the spring 31 will be compressed, the damper 21 being then closed. As the velocity of the airplane decreases, as in landing, the spring 3| is capable of moving the plunger forwardly so as to open the damper by means of the levers. The lower the velocity is, the more will the damper be opened, so as to adjust itself into an extreme position crosswise over the air inlet passage 29. The two dampers 21 will thenclose this passage entirely, so that all air to the compressor will be taken from the boundary layer through the conduits 15,

The suction through the branch conduits 24 may be controlled separately, if the suction slots 26 of these conduits be placed as shown in Fig. 2, that-is to say in the rear edge of the wing 2 in front of awing flap 2. The slots 26 will be opened only when the wing flaps are lowered for braking,

the wing flap and the boundary layer control then and escaping through the outlet 1 may be reduced at the same time or changed with respect to the direction thereof, which is effected with the aid of the deflector flaps [0, II mentioned hereinbefore. These flaps may be operated separately or with members coupled to the control dampers 21 for the passages l5, l6, aswill be described more closely in the following.

According to Fig. l, the boundary layer control is eflected solely by the suction ot-air iromthe boundary layer. It is-also-appropriate, however, as shown in Figs. 3-4, to actuate the boundary layer by blowing air through suitable exhaust slots in the airplane, particularly in the covering of the wing, but, ii. desired, also in that of the fuselage. For this purpose conduits 438' mayextend from the pressure side of the compremor I orfrom some other pressure outlet of the com- =pressor to suitably arranged exhaust slots: 39,10 which the air is conveyed through a number of branch conduits 4'0. The slots 39 may also, as shown in Fig. 4, be located immediately intron't o! a wing 'flap A l (or an-aiileron) or, as -shown ln Fig.5 at .39', openon the 'lower side of the wing. Inadd-ition to the exhaust slots 39, thereare also provided suction slots 43 in the embodiment aooording to Fig. 3, such suction slots being located further forward :on the upper side of the wing. Air is being sucked through these slots over branch conduits 44 and a manifold extending 'inithe direction of thespan to a-mouth 46 in the wall of the unit behind the .alreintake =3on the suction side of the compressor- 4. 'I heimouth I6 may be controlled by meansof dampers 11 which may be actuated by springs 18 or the like, in a manner such that they are kept fo'lded'outso as to cut oil the air-dntaikei at :a low speed .01 the airplane while being closed against the mouth 46 on account of the pressure from 'the-air-fiowing through the air-intake at normal speed of flight. In the embodiment just described and shown in Fig. -3, sucking off :of the boundary layer may :obviously take place through the slots 43 simultaneously with boundary layer acceleration through the .air blown out through the slots :39.

In the .modifica'tion indicated in Fig. 5,-two rows .01 "branch conduits 44a, 44b are taken :to extend from the suction conduit. for the suction .0! air iromsuction slots 13a, 43b located behindone aniother -on the upper side of the wing at the :rear edge thereof. Air-is blowniorward'ithrough :the exhaust slots .39 arranged on the lower :side .of the wing. The .object' of :this arrangement is to permit ;an increase .of the circulation about :the

wing, whenrequiredandalso to permitacertain simultaneous braking. effect.

The simultaneous sucking and blowing opera.- tions b means of the compressor brings about a-reduction of the guantity vofair supplied to the combustion chamber and, consequently, involyes per-se a reduction of the propellin force.

In the embodiment shown in Figs. ,6 and 3'7, means are indicatedfor boundary :layer ,eontro'l in the form of suction slots 150., :Which are airranged on the upperside of the-Mined, :and of conduits 51 connected on each-,side of .the unit to the suction side-of the compressordl. Dampers .52 ,are provided to control .the mouths-,ofuthe-con- .duits 5| at the air inlet passage 29110 itheicompressor 4. Here, the means tor the boundary layer control may be supplemented -subsliflntially shown in Fig. 1 or .3. For :the control oi the direction and the m gnitude oLthe prqpellingreactionforce thereis gprovided ea'idefiectortarrange- ,ment at the rear edge of the wing at the outlet tor the greaction gasesaid :arrangementsbeing, in principle, of the same construction as that de scribed with reference to Fig- :Hfire. i QWE- QL thedefleotor :fiaps 10, ll are swingahle. saboutqa shaft I 2 extending ;in the direction gofrthegspan. Theyniay be adjusted each :per so. tha is :torsay be rextended with their ;rear .edges iagainstieach other :into the zposition designated thy t0! :they new he turned :toaetherdnio ianymi the-muons and l -l respectively.

6 d and .e. They may also take intermediate pool.- tions :between said extreme positions. In the position c, or .in'intermediate positions betweensaid qpositionand the completely retracted position (the initial position) the reaction gases aredeflected so that an -equal amount thereotwill flow out obliquee 1y forward and :upward as obliquely :iorward and downward, a portion also escaping straight rearward in intermediate positions. In the position 0, all gases are deflected obliquely forward and 'upward and in the position d obliquely forward and downward. This shifting of the deflecting means may be effected manually or automatically, pmierably inconnection with the landingof the airplane. The shifting is efiected so that the deflector device is turned upward, for instance from thepositlon d, in which the reaction gases fiow .obliquely downward and cause a lifting force at therea-r edge of the wing, to the position awhen the airplane touches the ground, or immediately before, so'that the gases are thendirectedobliquely upward and forward, entirely or inpart. Here'- "by, the buoyancy on the wing is annihilated, the airplane being thus pressed to the ground.

Operating members tor the shifting of the dc fiector or braking device may be coupled to op-- crating members for the "boundary layer control in various ways. The coupling may be such that the deflector flaps are folded out successively into the deflecting position or the braking position, according-as the dampersareopened'for the boundary layer control. In combination themwith, a coupling may :be made use of, which is such that the actuation of theboundary layer is caused to cease, entirely or in -:part, when the deflector device is turned up, that is to :say, shifted, for instance, from the position d'to the position-e in Fig. 6, forexample. Hereby, the air pressure on the wing will decrease, partly on ac,- -count of cessation of the actuation of the boundary layer, and partly because of the fact that the gases flowing Iorward over the wing annihilate the buoyancy. The first mentioned coupling :is shown "diagrammatically in Figs. 8 and!) and may be particularly conceived as applied to the em.- bodiment according to Fig. 1. The second-con! pling referring to units in the wing according to Figs. 6 and .7 is shown in 10.

As will appear from Fig.- 8, a i-hand lever swingable about a :fixed shaft :55 is connected, *above said shaft, to theone endof two :links i9 through a link rod 51, said Llinks :having zthcir other .ends connected to the deflector flaps .lil Below the shaft 35.5,, the lever 55 is pivotally connected with twovarms 80, :which :are connected .each with .oneof the dampers for-the conduits 1.5, 1.5 for the boundary layer control. When the-supper .end .of the lever is 'swung rearward, for instance .into the position indicated :by chain-.dotted lines, the dampers 21 are opened simultaneously withithe dolding-out of the deflector :flaps Hi, i! iiIltO :a deflecting position (chain-dotted lines), where the gases may flow :iorwardly, entirely or in :part, as indicated by the arrows 6|. Hereby 'alsi-mulr taneous boundary layer control .and reactive braking will be obtained. "I -hisoperation :iscarried out in landing immediately before the airplane touches the ground. .Atthe very moment of touching: theiground .it may .be :found suitable to disconnect .theiboundary layer .control, .while braking is continued and augmented, .if desired. Toithis end, .the connection ,of .the'lever 255 with arms in may be 5 disconnectible, manually :3)! automatically. in the latter base for flirough arr-impulse from the undercarriage. or from-some scanning or feeling member suspended from-the: airplane; The disengageable connection between the'lever 55 and the arms 68 is shown in a perspective view in Fig.- 9, while an example of the arrangement of an impulse'from the undercarriage is shown in a portion of Fig. .10, a modification'thereof'being shown in Fig. 11. According to Fig. 9, the-lever .55 is bifurcated at the bottom, a coupling catch 55 being mounted on a bolt between the shanks 63 of the fork, .thehook-shapedend of which catch clasps about .a projection 65 onthe en'dofthe one arm 68-. .A spring 61 inserted between the other. end -of the .catch and the fork tends to keep the catch in engagement with said projection. Secured to the fork is an electromagnet 58, which may be connected-through wires 59, I8 to a contact device, by means of which the circuitmay be closedover -the-electromagnet. This contact device may be .constructed as described with reference to Fig. 10 or 11. When the circuit is closed, the hook will be attracted and raised into the position indicated by chain-dotted lines so as to be disen-r gaged from the projection 56 while. releasing the arms 58. Y

The arrangement shown inFig; 10 to fold the deflector flaps I8, II out and in and to swing them upward and downward about the common axis of rotation I2 is constructed in the following manner.- Pivotally secured to theside piece of each deflector flap is the one end of an arm ;'I2,-the other end of these arms being mutually connected by a bolt 13. At a point between the ends of each arm, a forward directed link rod 14 is pivotally connected with the same. The fore ends of the link rods I4 areconnected with each end of a transverse .rod 15. Extending through the centre of the latter is a forwardly directed shaft I6 the fore end of which is formed into a screwentering the rear end of a rod 11 provided with a threaded bore. Securedon the fore end of the rod 11 is a toothed segment .18, which is actuated by a pinion I9 on a shaft 88 of an electric motor 8|, said shaft extending at right angles to the rod". The other end of the motor shaft 88 actuates, over a bevelled gearing 82, the shaft of the damper 52 (compare Fig. 7) controlling the conduits I from the suction slots .58 in the wing 2. The shaft I6 is driven by a motor 83, which is suspended so as to permit. dis? placement of the shaft in the longitudinal direction thereof as well as a swinging movement of the shaft about a geometric axis of rotation extending in the direction of the span through the mounting point of the transverse rod I5 on the shaft I5. The motor BI is connected into a circuit comprising. a source of current 84, wires 85, and 81 and a pair of contacts 88, 89, of

which the one contact 88 is secured to the upper and the other contact 89 to the lower one of the two telescopically cooperating members98 and BI respectively constituting the legs of the undercarriage. A wheel. of the under-carriage is denoted by 92.

i The arrangement shown in Fig. 10 operates in the following manner:

It is assumed that the deflector flaps I8, I I tak initially the position shownby full lines in Fig. 10, the flow of reaction gases having been deflected so as to be directed substantially obliquely forward and downward. This position is the one existing immediately before the airplane touches the ground. The dampers 52 are then folded out so asto out off the forwarddirected air-intake.

the circuit over the motor BI.

' .I 8,,so that the transverse rod I5 is moved ob.-

liquely into the position marked by dash lines 15'. Hereby the deflector flaps I8,- II will be turned through the. agency of the link rods-:14 about the common axis I2.=in-to theposition shown by chains'dotted lines. This-involves that the flow of exhaust gases, which was-previously directeddownward, is now directed upward above the upper side of the wing. While this swinging of the flaps I8, II takes place, the motor 8i turns the damper 52 over the gearing 82, so that" this damper is swung from the position shown by full lines inward toward the mouth of the passage 5| so. as to close the latter. The boundary layer controlwill thus be interrupted. The buoyancy on the upper side of the-wing is annihilated by the exhaust-gas flow, which in connection with the other measures of expediency results in that the airplane touches the ground forcibly.

The deflector flaps are folded in and out with the aid-of the motor 83, which is'adapted to displace thetransverse rod I5 forward or rearward by -:the fact that the screw I5 when rotated by means of the motor is retracted into or projected from the rod 11 provided with inner screw threads. I In the modification according to Fig. 11, the contacts 88, B9 are closed by a suspended reeler 94, preferably in'the form of a resilient rod, which is swingable" about a shaft 95 and carries the contact 88 on the upper end thereof. Whenthe rod abuts the ground so as to swing rearward with its lower end, the contacts are closed, so that the deflector flaps will be'shifted in the manner described with reference to Fig. 10. Although-the arrangement'described with ref.- erence to Fig. 10 has been shownas applied to units builtqinto a wing, the same arrangement may be provided, inapplicable parts;:in"units 'which are arranged centrally on the fuselage accordingtoFig-l. Fig. '12 shows an embodiment,'wherein the re action gases are not deflected by means of flaps but by being directed into forward directed pas sages opening" forward into the air-intakes 3. Such a passage I88 is provided on each side'of the unit. Provided in the mouth between the central gas exhaust tube I and these passages I88 are valve members. 'or dampers 'I8I, I8I', which may be operated automatically or manually, the same being kept closed, for instance in normal operation, by'means of a spring I82, as in the damper I8I, or being provided with an arm I83,

which is connected to a manually operable rod I 84 or the'like, as shown in the damper I8 I The outlet of the passages I88 into the air-intakes 3 may,*like'the latter, be controlled on each side by means of common-valve members or dampers I85 arranged onthe same shaft I88 as the damp ers I8'I for the boundary layer control in the mouth of the passages I88 from suction slots I88 in the airplane wing. The dampers I85 may be swung from the position shown by full lines, wherein they close the mouths of the passages, toward the inner wall of the air-intake soas to cut off the air supply from the front throughthe air intake-3. Inzthe normal outlet 9 of-the unit there is provided an axially displaceable conical member H0, whichm-ay-be caused to'close against a seat I I I on the wall of the exhaust passage.

In normal operation without braking, the dampers take the positions shown by full lines, the rear as well as the front mouths of the passages I being then closed. If the airplane i to be braked, for instance in landing, the conical throttle member III] is moved rearward, so that the outlet 9 is closed more or less. By reason of the increase of the pressure in the tube i in front of the throttle member, the damper II'II will be opened against the action of the Spring I02, so that the gases will instead flow out forward so as to cause rearward directed reaction forces. The dampers I are shifted by the gas flow, so that the air-intakes 3 are closed. At the same time, the dampers I01 secured on the same shaft I06 are swung out so as to open the mouths of the passages I08 for the boundary layer control. Consequently, boundary layer control and braking will be possible at the same time.

;The forms of embodiment described may be supplemented so that the operating members for the control of the actuation of the boundary layer and/or the reactive braking and the lateral exhaust of the gases are associated, entirely or in part, with one or more of the control levers (rudder pedals) for the operation of the airplane or with the control member for the reaction motor (the gas' lever) or for the number of revolutions thereof.

Furthermore, there may be provided, in additionto the lever or the like adapted for the control of the degree of the actuation of the boundary layer and/or the reactive braking, coupling devices adapted to connect the braking device with guide members for the course steering of the airplane, so that the braking efiect may be distributed to the right and left, according as these throttle members are adjusted for a corresponding change of the course.

What I claim is:

1. In anaircraft, an internal combustion turbine unit including means providing an air in take passage, a compressor, a combustion chamber, a turbine coupled to said compressor and a rearwardly directed jet discharged nozzle connected in series to deliver air for combustion under pressure from said compressor to said combustion chamber and gaseous products of combustion from the combustion chamber through said turbine and jet discharge nozzle for propulsion of the aircraft; an exterior aircraft surface having slots therein, interior duct means extending from the compressor to said slots in the exterior surface to effect boundary layer control, whereby the boundary layer control efiect may be increasedby increase in speed of the turbine unit; and adjustable deflector means movable into the path of combustion gases passing from said combustion chamber through said jet discharge nozzle to direct a portion of the propulsive gases forwardly to neutralize the potential increase in propulsive effect due to increase in speed of the turbine unit for boundary layer control. 4

2. In an aircraft, an internal combustion turbine unit including means providing an air intake passage, a compressor, a combustion chamber; a turbine coupled to said compressor and a rearwardly directed jet discharge nozzle connected in series to deliver air for combustion underpressure from said compressor to said combustion chamber and gaseous products of'combustion from the combustion chamber throughhector means movable into the path of combustion gases passing from said combustion chamber through said jet discharge nozzle to direct controlled amounts of said gases forwardly to produce a braking force on the forward motion of the aircraft variable from zero to a maximumdepending on the position of adjustment of said dehector means to neutralize the potential increase in propulsive 'enect due to increase in speed of the turbine unit for'boundary layer control.

3. In an aircraft, an internal combustion turbine unit including, means providing an air intaxe passage, a compressor, a combustion chain her, a turbine coupied to'said compressor and a I'earwaruly directed Jet discharge nozzle con nected in series to deliver air for combustion under pressure from said compressor to said combustion chamber and gaseous products OI combustion from the combustion chamber through said turbine and jet discharge nozzle for propulsion of the aircraft; an exterior aircraft surface having slots therein, interior duct means extending from the pressure SIOJB'OI the compressor to said slots in the exterior surface to effect boundary layer control, boundary layer control effect may be increased by increase in speed of the turbine unit; and adjustable denector means movable into the path of combustion gases passing from said combustion chamber through sale. et discharge nozzle to ulrect controlled amounts of said gases forwardly to produce a braking force on the forward motion of the aircraft variable from zero to a maxi mum depending on the position of adjustment of said denector means to neutralize the potential increase in propulsive effect due to increase in speed of the turbine unit for boundary layer control.

4. An aircraft as claimed in claim 1, said de- I flector means comprising a throttling member for shutting off the gas outlet rearward through said jet discharge nozzle and means providing a passage directed substantially forward to conduct the combustion gases from a point ahead the outletbut aft the compressor and out to the atmosphere. 1 v

5. An aircraft as claimed in claim 2, said deflector means comprising a throttling member for controlling and shutting off the gas outlet rearward through said jet discharge nozzle, means providing a passage directed substantially forward and connecting the gas outlet of the unit with the air intake thereof, and a control device to shut off the air supply to the unit through said intake whereby the air to the'compressor is drawn from the boundary layer simultaneously with the flow of the combustion gases out forward through the air intake;

6. An aircraft as claimed in claim 2, said deflector means comprising athrottling member for controlling and shutting oif the gas outlet rearward through said jet discharge nozzle, means providing a passage directed substantially forward and connecting the gas outlet of the unit whereby the with the air intake thereof, and a control valve common for the air intake and said passage and mounted to be opened by the gases flowing.

through the passage to the air intake and to simultaneously close the passage from the air intake to the compressor.

7. In an aircraft the combination of a jet the increase of pressure created as a result of throttling the outlet passage by said throttling member.

8. In an aircraft the combination of a jet propulsion unit including a compressor, a combustion chamber and an outlet passage for the combustion gases, an exterior aircraft surface having slots therein, ducts connecting said slots to the intake side of said combpressor whereby to utilize said compressor for boundary layer control. a throttle member in the outlet passage, a passage extending from the outlet passage and opening forward, a valve for controlling the com munication between said passages and an operating member for manual control of said valve.

9. In an aircraft having a .wing, an internal combustion turbine unit carried by the aircraft including means, providing an air intake passage, a compressor, a combustion chamber, a turbine coupled to the compressor and a rearwardly directed jet discharge nozzle connected in series to deliver air for combustion under pressure from said compressor to said combustion chamber and gaseous, products of combustion from the combustion chamber through said turbine and jet discharge nozzle for propulsion of the aircraft, said wing having slots spaced along the length and opening on the surface thereof, conduits extending through the wing connecting said compressor with said slots for boundary layer control whereby the boundary layer control may be increased by increase in speed of the turbine unit, means for controlling flow through said conduits to vary the boundary layer control at different points'along the length of'sai'd wing, adjustable deflector means movable into the path of combustion gases passing from said combustion chamber through said jet discharge nozzle to direct at least a portion of said gases forwardly to produce a braking force on the aircraft, and means for adjusting the position of said deflector means to control the amount of said braking force to neutralize the potential increase in propulsive effect due to increase in speed of the turbine unit for boundary layer control.

10. An aircraft as claimed in claim 9, in which the means for controlling flow through the conduits connecting the compressor to the wing slots comprises a member responsive to the pressure of the ambient airwhereby to control the flow automatically in accordance with the speed of the aircraft.

11. An aircraft as claimed in claim 9 in which the means for controlling flow through the conduits connecting the compressor and wing slots comprises damper members responsive to the pressure of air in the air intake passage.

12. In an aircraft having awing, an internal combustion turbine unit carried by the aircraft including means providing an air intake passage, a compressor, a combustion chamber, a

turbine coupled tothecompressor and a rearwardly directed jet discharge nozzle connected in series to deliver air for combustion under from said compressor to said combustion chamber and gaseous products of combustion from the combustion chamber through said turbine and jet discharge nozzle for propulsion of the aircraft, said wing having a plurality of slots in spaced relation opening on the surface thereof, a conduit connecting some of said slots with the suction side of the compressor,- another conduit connecting other of said slots with the pressure side of the compressor, whereby to effect boundary layer control by simultaneous removal of air by suction and blowing through the respec-- tive slots, adjustable deflector means movable into the path of combustion gases passing from said combustion chamber through said jet discharge nozzle to direct at least a portion of said gases forwardly to produce a braking force on the aircraft, and means for adjusting the position of said deflector means to control the amountof braking force, the arrangement being suchthat the boundary layer control effect may be increased by increase in speed of the turbine unit and the braking force may be adjusted toneutralize the potential increase in propulsivethrust due to increase in speed of the turbine unit for increased boundary layer control.

13. An aircraft as claimed in claim 12 in whic the slots connected to the suction side of thecompressor are positioned forwardly of the slots combustion air under pressure to said combustion chamber for burning with fuel to produce the propulsion gases and a rearwardly directed jet discharge nozzle for said gases, conduits connecting the surface slots in said wing to said compressor to control the boundary layer at the wing through the compressor whereby the boundary layer control may be increased by increase in speed of the jet propulsion unit, movable defiecting means associated with the jet discharge nozzle adjustable to a position for deflecting the propulsion jet downwardly and forwardly beneath the wing, and means for adjusting the position of said deflecting means to neutralize the potential increase in propulsive effect due to increase in speed of the jet propulsion unit for boundary layer control.

16. In an aircraft, the combination of a wing having surface slots therein, a jet propulsion-unit carried by the wing including a combustion chambers, an air compressor for the supply of 1 combustion air under pressure to said combustion Y chamber for burning with fuel to produce the propulsion jet gases and a rearwardly directed i jet discharge nozzle for said gases, conduits connecting said surface slots in'the wing to said compressor to control the boundary layer at the wing through said compressor: whereby the boundary layer control may be increased by in-- crease in speed ofthe jet propulsion unitpde 5 fleeting means associated with the jet discharge propulsion jet forwardly for braking purposes andicoupled operating members for adjusting the position of said deflecting means andifor controllingthe passage of air to said compressor throughsaidconduits whereby to, ,iieutralize the potential increase in propulsive effect due to increase in speed of the jet propulsion unit for boundary layer control.

17. In an aircraft having a wing, aninternal combustion turbine unit carried by the aircraft" wardly directed jet discharge nozzle connected in series to deliver air for combustion under pressure from said compressor to said combustion chamber and gaseous products of combustion from the combustion chamber through said turbine and jet discharge nozzle for propulsion of the aircraft, said wing having slots opening on the upper surface thereof, conduits extending through the wing connecting said compressor to said wing slots for boundary layer control, control members for regulating the flow through said conduits, reaction braking means comprising adjustable deflector members mounted adjacent the outlet of said jet discharge nozzle, operating means for adjusting the position of said deflector members to braking positions to deflect the gases issuing from said nozzle forward entirely above, entirely below or partly above and partly below said wing and connections between the control members for regulating the flow through said conduits for boundary layer control and said operating means for adjusting said deflector members effective to reduce the boundary layer control when said deflector members terior surface of the aircraft to said unit and including a wall, a shutter means normally forming a part of the wall of said intake passage but movable to a position to partially block said passage so as to cause a relative depression in the pressure of the fluid in said passage downstream of said shutter means, and a means in' said wing providing a passage between an opening in the upper surface of the wing near the wing tip and an opening in the wall of said intake passage, which last named opening is normally closed by said shutter means but which is uncovered, when said shutter means is moved as aforesaid, to place that portion of said intake passage which is downstream of said shutter means in communication with said wing tip opening, whereby to remove some of the boundary layer from the upper surface of the wing tip.

19. An aircraft having a wing, an internalcombustion turbine unit carried by the aircraft, means providing an air intake passage for said unit extending from an exterior surface of the aircraft and including a wall, shutter means normally forming part of the wall of said intake passage but movable to a position to partially block said passage so as to cause a relative de- I4 pressiori inthe pressure of fiuitf iii said assage downstream of said shutter means, and means providing a; passage between .an opening in the upper surface ofthe wing andan opening in the wall of said intake passage,- which last-named openin'gisnormally closed bythe shutter means, buhwhichis uncovered when the shutter, means is moved as aforesaid, to place that portionof the intake passage which is downstream of said shutter means in communication with said wing opening, whereby to removesome of the bou n d;l ary layer from the upper surface of said swing. 1 20. An aircraft having a wing, an internalcombustion turbine unit carried by the wing, a means providing a streamlined intake passage for said unit, said means extending from an exterior surface of the aircraft to said unit and including a wall, a shutter means normally forming apart of the wall of said intake passage but movable to a position to partially block said passage so as to cause a relative depression in the pressure of the fluid in said passage downstream of said shutter means, an aircraft control member, a connection between said shutter means and said control member whereby said shutter meansis moved as aforesaid when said control member is moved in one direction and a means in said wing providing a passage between an opening in the upper surface of the wing near the wing tip and an opening in the wall of said intake passage, which last-named opening is normally closed by said shutter means but which is uncovered when said shutter means is moved as aforesaid, to place that portion of said intake passage which is downstream of said shutter means in communication with said wing tip opening, whereby to remove some of the boundary layer from the upper surface of the wing tip.

21. An aircraft having wings, an internal combustion turbine unit carried by the aircraft, means providing a streamlined intake passage for said unit, said means extending from an exterior surface of the aircraft to said unit and including a wall, oppositely-disposed shutters which normally form separate parts of the wall of said intake passage but which are movable to a position to partially block said passage so as to cause a relative depression in the pressure of the fluid in said passage downstream of said shutters, and means providing passages between openings in the upper surfaces of the wings and openings in said separate parts of the wall of said intake passage, which last-mentioned openings are normally closed by said shutters re- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,493,280 Rees May 6, 1924 1,854,043 Korner Apr. 12, 1932 2,024,274 Campini Dec. 17, 1935 (Other references on following page) UNITEDi STATES PATENTS Number Anxionnaz et a1. Mar. 19, 1946 Martin June 11, 1946 Stalker Sept. 3,- 1946 Number OTHER REFERENCES s er. No. 396,458, Richard (A; P. 0.), published ay'25,1943.- y i Y 

